There0s a lot more to poker than it just being a game of cards: in fact, along with chess, it's probably one of the two most complicated games that we humans play.
The first complication is that there are so many different variations of the game. Hold'em uses different tactics and strategy (or rather, requires different...to be successful) from Omaha or Seven Card versions of the game. The odds are different of different hands, for example, the portion of the pack that you can see is different and so on.
The second important point is that what actually happens with the cards is the least important part of the game. They are a foil, only , certainly at the higher levels, what you do with your hands while you play the real game. That is, while you play the hopes and reactions of the other humans sitting around the table.
For that's what poker is really about, reading other people, working out what they're doing, and then changing your own tactics to match that.
These two sets of complications lead to it being necessary for you to understand the various strategies you should be employing. Fortunately, there's a great web site set up to explain just these to you. Try it out here, poker strategy explained to you, all the variations of the game.